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lcd_io_8

Anobium edited this page Oct 18, 2020 · 1 revision
LCD_IO 8

Using connection mode 8:

Using connection mode will require R/W, RS, Enable and all 8 data lines.

The data lines must all be connected to the same I/O port, in sequential order. For example, DB0 to PORTB.0, DB1 to PORTB.1 and so on, with DB7 going to PORTB.7.

Relevant Constants:

These constants are used to control settings for the Liquid Crystal Display routines included with Great Cow BASIC. To set them, place a line in the main program file that uses #define to assign a value to the particular constant.

Constants are required for 8-bit mode as follows.

Constant Name Controls Default Value
LCD_SPEED FAST, MEDIUM or SLOW. MEDIUM
LCD_IO The I/O mode. Can be 2, 4 or 8. 8
LCD_RS Specifies the output pin that is connected to Register Select on the LCD. Must be defined
LCD_RW Specifies the output pin that is connected to Read/Write on the LCD. The R/W pin can be disabled*. Must be defined (unless R/W is disabled)
LCD_Enable Specifies the output pin that is connected to Read/Write on the LCD. Must be defined
LCD_DATA_PORT Output port used to interface with LCD data bus Must be defined
LCD_LAT Drives the port with LATx support. Resolves issues with faster Mhz and the Microchip PIC read/write/modify feature. See example below. Optional

The R/W pin can be disabled by setting the LCD_NO_RW constant. If this is done, there is no need for the R/W to be connected to the chip, and no need for the LCD_RW constant to be set. Ensure that the R/W line on the LCD is connected to ground if not used.

For a code example download Eight Wire LCD example.

For code examples see Eight Wire Examples.

See the separate sections of the Help file for the specifics of each Connection Mode.

For more help, see LCD_IO 0, LCD_IO 1, LCD_IO 2, LCD_IO 2_74xx164, LCD_IO 2_74xx174, LCD_IO 4, LCD_IO 10 or LCD_IO 12

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